• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.50 no.9
• /
• pp.431-439
• /
• 2001

This Paper illustrates a new numerical analysis method using a nodal effective load model for nodal probabilistic production cost simulation of the load point in a composite power system. The new effective load model includes capacities and uncertainties of generators as well as transmission lines. The CMELDC(composite power system effective load duration curve) based on the new effective load model at HLll(Hierarchical Level H) has been developed also. The CMELDC can be obtained from convolution integral processing of the outage capacity probabilistic distribution function of the fictitious generator and the original load duration curve given at the load point. It is expected that the new model for the CMELDC proposed in this study will provide some solutions to many problems based on nodal and decentralized operation and control of an electric power systems under competition environment in future. The CMELDC based on the new model at HLll will extend the application areas of nodal probabilistic production cost simulation, outage cost assessment and reliability evaluation etc. at load points. The characteristics and effectiveness of this new model are illustrated by a case study of MRBTS(Modified Roy Billinton Test System).

• Structural Engineering and Mechanics
• /
• v.83 no.6
• /
• pp.745-756
• /
• 2022

This study aims to determine the cause of the load resistance loss in storage racks that can be attributed to external forces such as earthquakes and to improve safety by developing reinforcement systems that can prevent load resistance loss. To this end, a static cyclic loading test was performed on pallet racks commonly used in logistics warehouses. The test results indicated that a pallet rack exposed to an external force loses more than 50% of its load resistance owing to the damage caused to column-beam joints. Three reinforcement systems were developed for preventing load resistance loss in storage racks exposed to an external force and for performing differentiated target functions: column reinforcement device, seismic damper, and viscoelastic damper. Shake table testing was performed to evaluate the earthquake response and verify the performance of these reinforcement systems. The results confirmed that, the maximum displacement, which causes the loss of load resistance and the permanent deformation of racks under external force, is reduced using the developed reinforcement devices. Thus, the appropriate selection of the developed reinforcement devices by users can help secure the safety of the storage racks.

• Steel and Composite Structures
• /
• v.24 no.1
• /
• pp.23-35
• /
• 2017

Current form of Corrugated-strip connectors are not popular due to the fact that the two ends of this form need to be welded to steel face plates. To overcome this difficulty, a new system is proposed in this work. In this system, bi-directional corrugated-strip connectors are used in pairs, and only one of their ends is welded to the steel face plates on each side. The other end is embedded in the concrete core. To assemble the system, common welding devices are required, and welding process can be performed in the construction sites. By performing the Push-out test under static loading, the authors experimentally assess the effects of geometric parameters on ductility, failure modes and the ultimate shear strength of the aforesaid connectors. For this purpose, sixteen experimental samples are prepared and investigated. For fifteen of these samples, one end of the shear connectors is welded to steel face plates, and the other end is embedded in the concrete. Another experimental sample is prepared in which both ends are welded to the steel face plates. According to the achieved results, several relations are proposed for predicting the ultimate shear strength and load vs. interlayer slip (load-slip) behavior of corrugated-strip connectors. Moreover, these formulas are compared with those of the well-known codes and standards. Accordingly, it is concluded that the authors' relations are more reliable.

• The KIPS Transactions:PartA
• /
• v.8A no.4
• /
• pp.299-310
• /
• 2001

In this paper, we study the methodology of distributing the requests of clients based on the state of real server in the LVS(Linux virtual server) clustering system. The WLC(weighted least connection) algorithm in the LVS cluster system is studied. The load distributing algorithm which assigns a weight into each real server is devised by considering the load of real servers. The load test is executed to estimate the load of real servers using a load generating tool. Throughout the result of the experiment, we suggest new load distributing algorithm based on the usage of physical memory of each real server. It is shown that the correction potentiality of new algorithm is somewhat better than that of the WLC algorithm.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.983-985
• /
• 2002

This paper is the machine that is able to estimate a new built power convertor in a production line. Generally, this machine test can be achieved by connecting it to a dynamometer consisting of a three-phase machine joined by a rigid shaft to a DC load machine. But the proposal system is controlled to create some specific load characteristic needed for the test without any mechanical equipment. The suggested test stand consists only of a converter to be test and a simulator converter. Both devices are connected back-to-back on the AC-side via smoothing reactors. The simulator operates in real-time as an equivalent load circuit, so that the device under test will only notice the behaviour of a three-phase machine under consideration of the load. And then, to obtain a superior characteristic for dynamic reference used the feedforward control.

• Transactions of the Society of Information Storage Systems
• /
• v.5 no.2
• /
• pp.82-88
• /
• 2009

Understanding the adhesion behavior and characteristics of toner film is required to achieve image and text printing with high quality resolution. Toner can be considered as a thin film coating on a media such as paper or polymer film. Quantitative measurement of adhesion characteristics of the thin film is important to assess the reliability of the system. In this work the main objective was to investigate the adhesion characteristic between the toner and the media by ramp loading scratch test method. The scratch test may be used to obtain quantitative information about the adhesion of the film to the substrate. In the scratch test a diamond tip was used to scratch the surface of the toner film under an increasing normal load until the toner detached or fractured. The critical load (LC) was obtained from the experimental results. Also, the relationship between the critical load and the adhesive strength of the interface between the substrate and the toner was obtained by measuring the normal and tangential forces during the scratch test. Finally, theoretical analysis of the toner scratch characteristics was performed based on Benjamin and Weaver theory, Plowing model, and Laugier model.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.357-367
• /
• 2010

In this study, several design and construction cases of the pile bent system for bridges were introduced. The lateral displacement of the pile bent system is larger than the displacement of pile cap system, due to the smaller bending stiffness and the longer unsupported length. So, the analysis of the lateral pile displacement is main factor for the design of pile bent system and superstructure. For the accurate estimation of the pile displacement, an iterative analysis method was developed. The superstructure was analyzed regarding the pile foundation as $6{\times}6$ spring and the substructure was analysed using non-linear load transfer curves (p-y, t-z, q-z curve). And, to verify this analysis method, the estimated displacements are compared with the results of lateral load test. This analysis method is expected to be a viable alternative approach for the design of bridge foundation hereafter.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.6
• /
• pp.2035-2049
• /
• 2015

Applications deployed in cloud receive a huge volume of requests from geographically distributed users whose satisfaction with the cloud service is directly proportional to the efficiency with which the requests are handled. Assignment of user requests based on appropriate load balancing principles significantly improves the performance of such cloud-based applications. To study the behavior of such systems, there is a need for simulation tools that will help the designer to set a test bed and evaluate the performance of the system by experimenting with different load balancing principles. In this paper, a novel architecture for cloud called Request Assignment Simulator (RAS) is proposed. It is a customizable, visual tool that simulates the request assignment process based on load balancing principles with a set of parameters that impact resource utilization. This simulator will help to ascertain the best possible resource allocation technique by facilitating the designer to apply and test different load balancing principles for a given scenario.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.562-564
• /
• 1995

This paper proposes a new algorithm for maintenance scheduling with considering load forecast uncertainty. The proposed algorithm is based on the equivalent load of effective load carrying capability(ELCC) of generators. The uncertainty of forecasted load is considered as a normal distribution probability density function. For maintenance scheduling, reserve levelization method and risk levelization method are used in this study. To test the algorithm, we applied the proposed method to IEEE reliability test system(IEEE RTS). As a result, we verified the validity of the proposed method.

• Journal of Biosystems Engineering
• /
• v.11 no.1
• /
• pp.8-16
• /
• 1986

This study was carried out to develop a microcomputer-based data acquisition system for engine performance test. A low-cost data acquisition system was developed utilizing an "APPLE II PLUS" microcomputer. The developed system consists of microcomputer, RPM counter included frequency-to-voltage converter, preamplifier for two load cells and 8-bit analog-to-digital converter with 16 chnnels. The system simultaneously measures engine speed by means of photointerrupter, torque and fuel consumption by means of load cells with variable sample numbers, sampling intervals and repetitions. The system collects, processes and provides data for storing on the $4{\frac{1}{4}}$ inch floppy disk as well as for writing out on the printer.